4 The Early Life of the Young Cuckoo. 



Although we have accomplished this much, we 

 have not yet proved in any way why the egg is so 

 very small in comparison with the size of the bird, 

 but my friend, Mr. John Craig, to whom I shall 

 shortly refer, has, so far as I am aware, produced 

 the best explanation of this by stating that he con- 

 siders it is for the purpose of quick incubation and 

 to allow the egg to be deposited in birds' nests 

 which are smaller than the Cuckoo, and also to 

 allow the Cuckoo to carry the egg in her bill to its 

 destination without breaking it. 



As to why the bird does not build a nest for 

 itself, my friend also puts forward the theory that if 

 it did, and laid four or five eggs to the clutch, one 

 on each successive day, the instinctive desire im- 

 planted in the young Cuckoo of clearing everything 

 out of the nest in which it is hatched, is so strong 

 that there would be a struggle among them for 

 possession of the nest, the weakest would perish, 

 and they would be in a worse position than at 

 present for perpetuating their species. Mr. Craig 

 thinks that it is incompatible with the perpetuating 

 of their species for more than one ^gg to be deposited 

 in the same nest. I must say that, so far, these ob- 



